In automation engineering, field bus devices are used in order to control bus subscribers with the aid of process data or to pick up process data from bus subscribers for further control and/or monitoring. The field bus devices are usually configured using a superordinate computer which is connected to a configuration interface or via the field bus to the field bus device. The configuration is usually performed on the field bus couplers, which are a special form of field bus devices which can firstly be connected via a field bus to superordinate or coordinate devices and to further field bus couplers or control/monitoring computers and can secondly be connected via an internal (field) bus to further field bus devices in the form of input and/or output modules (I/O modules).
One particularly advantageous configuration option for processor-controlled devices is provided by what are known as web server platforms, which are implemented in the device to be configured and allow data interchange with a configuration device using the TCP/IP (Transmission Control Protocol/Internet Protocol) protocol and the HTML-based Internet transmission standard. A web server has the advantage of being platform-independent. In this case, the communication guidelines are implemented in the field bus device, and the configuration device requires only a generally valid browser (e.g. Internet Explorer from Microsoft or Firefox) to display the content of the web server platform. The installation of a specific configuration program in the configuration device is not required. On the contrary, the configuration platform is implemented at run time by the field bus device in the browser of the configuration device.
A web server can be used not just to set parameters but also to perform more complex configurations. Thus, the web server can be used to provide a complex development environment for programmable field bus devices, for example, in order to set up said field bus devices and to create programs for the field bus devices, as disclosed in DE 10 2004 045 240 A1, for example.
However, a web server platform requires an Ethernet interface between the field bus device and the configuration device in order to allow data interchange by means of the TCP/IP protocol data packets between the field bus device and the web server platform implemented thereon and the configuration device.
The implementation of a web server platform in a field bus device is known from DE 103 47 007 A1, for example. The function blocks equipped with a web server function can be called by superordinate devices, such as control systems or control units, via Ethernet-compatible field buses and provide information as HTML pages in a general description language.
Since web servers are based on a TCP/IP protocol and the Ethernet data transmission standard, web servers have to date been able to be used in field bus devices only if such an Ethernet interface is present.
On the other hand, web servers provide the advantage of providing a platform-independent, general configuration platform, and may significantly reduce the development and configuration complexity.
US 2002/0178295 A1 describes a USB access point, managed by remote control, to a multiplicity of different kinds of USB peripheral devices using a web server implemented with a service provider. The USB access point is accessed via an Ethernet interface and the Internet. A protocol converter is provided in the USB access point in order to convert information transmitted via the Internet in the TCP/IP format into a protocol which is compatible with the USB standard and with the USB peripheral device connected to the USB interface.